The present invention generally relates to electrophotography and more particularly, to a developing apparatus for use in an electrophotographic apparatus and the like.
Conventionally, in a developing apparatus to be used in an electrophotographic apparatuses, etc., for electrically charging uncharged toner supplied into a developing apparatus thereof, it has been a common practice to charge the toner through depression thereof by a blade or the like, or through friction thereof with carrier and the like.
However, in the case where toner is adapted to be charged through contact by the blade or friction with respect to carrier, etc. as described above, there have been such problems that the toner may be crushed in some cases or that a considerable time is required for rising in the charging speed of toner, with a consequent poor response characteristic, while the charge amount of the toner is not stabilized in a proper range, thus resulting in fogging in the image to be formed or giving rise to scattering of toner.
In the arrangements which employ the electric field curtain device as referred to above, however, charging characteristics of toner have not yet been fully improved, with such problems as scattering of toner fogging due to insufficiently charged toner, etc. still being left unsolved.